May 29, 2014

46. Deformities of the Ear other than Microtia, Acquired defects and a note on the temporal fascial flap

46. Deformities of the Ear other than Microtia, Acquired defects and a note on the temporal fascial flap

Anomalies of the ear viz. anotia, microtia, bat ear, lop ear and a cup ear, as well as cryptotia have been described with illustrations in an earlier part of this blog (chapter 41). Of these, the lop and the cup ear as well as some forms of partial cryptotia may not appear as distinct or separate clinical entities and show some anatomical overlap. It is therefore practical to apply the basic plastic surgical thinking to these deformities and ask questions such as:

Is there a net tissue deficit ?

If there is such a deficit, of what nature it is? For example, in the ear, is it only skin or only cartilage or both?

In what manner can replacement of deficient tissue be achieved

If there is no net tissue deficit, then by what method can the abnormality be reconfigured to achieve an appearance as near normal as possible?

Reconstruction then follows according to a plan formed by the above information.

This chapter addresses not so much the treatment based on a rigid classification but tries to show a way for each problem at hand by asking and answering the questions narrated above. It should be noted here that in many post-traumatic situations either at the time of the injury or later when the wounds have healed the same analytical method can be applied to correct defects. The text that follows uses both kinds of abnormalities, traumatic and congenital to explain the principles of reconstruction with clinical examples.

In most lop ears tissue is adequate and only requires to be reconfigured. A lop ear (Fig. 1) is in fact somewhat of a bat ear in its upper one third (Fig. 2), the helical and anti-helical curves are not well formed and the otherwise normal (adequate) scapha is not retroverted and therefore lies limp in the forward direction (Fig. 1).

As stated above, because there is no net tissue deficit in many lop ears, the cartilage can be repositioned after degloving the skin (Fig. 3).

In some severe forms of the lop ear cartilage is deficient (particularly in the helical area), the ear therefore lacks an adequate spine and cartilage might have to be substituted to give the ear a normal appearance. This ear is neither a standard lop ear nor a cup ear (Fig. 4).

The cup ear also called the constricted ear is deficient both in its skin as well as the cartilage and that might include the scapha. In order to recreate the actual defect the ear might have to be cut across its breadth, the cartilaginous framework has to be replaced and then covered with a suitable flap (Fig. 5).

In many instances post-traumatic defects of the ear resemble those defects recreated by the plastic surgeon for a constricted ear as mentioned in paragraph 1 and the figure above (Fig. 5). A similar case is shown in figure 6 in which a post-traumatic defect which resembles a released constricted ear and where the wound has now healed is reproduced below (Fig. 6).

In some deformities of the ear the loss of cartilage and skin in the transverse axis is not considerable and therefore a compound flap of skin as well as the helical cartilage can be moved to bridge the defect (Fig. 7).

Apropos the text in the first paragraph of this chapter the case presented below represents a combination of a cryptotia like appearance because part of the cartilage is buried under the skin. There is gross deficiency of cartilage and skin. Here the tissue deficit has been estimated, replaced and covered (Fig. 9).

The ear is located in an area rich in vascularity. Its own blood supply is profuse mainly from the posterior auricular artery which sends an ascending branch in the auriculocephalic sulcus which supplies most of the auricle. The superficial temporal artery ascends in the front of the ear and supplies small branches anteriorly. What is more important, the occipital artery, the posterior auricular artery and the superficial temporal artery create a profuse network around the ear (Fig. 10). It is for this reason that flaps can be fashioned both in the front as well as behind the ear and sometimes small tube pedicles can be created to repair the helical curve when skin and cartilage is lost along the helical border (Fig. 11 and 12).

A flap can also be fashioned in an axial direction around the superficial temporal artery which supplies the subcutaneous fat and the superficial temporal fascia above the ear. going up to nearly 3 inches above its superior helical border and of enough breadth to cover almost the whole of the ear when rotated or turned over as an axial pattern flap. This flap containing only fat and fascia, is thin, just what is required for the ear and this in turn can be covered by a suitable skin graft which takes because of the flaps vascularity (Fig. 13). The dissection of the flap needs to be done with care by raising skin in the sub-follicular plane, but here too the skin survives and heals well because the scalp is equally vascular on either side. This flap can be used both for partial and complete loss of skin of the ear (Fig. 14).

Before avulsed skin is excised in fresh wounds a good inspection of the avulsed part as well as its base (or pedicle) is worthwhile because skin over the ear is known to survive both in the ante grade and retrograde direction as happens in the rest of the face and only very small pedicles will suffice. Sometimes the skin can be sutured back to see how it behaves for 48 hours and then can be excised if it necroses and the temporal fascia flap can be used as a cover for the cartilage with equally good results (Fig. 15).

The temporo-fascial flap alone can be used for cases of total reconstruction in microtia both with the help of autogenous cartilage as well as on a carved Medpore implant and can give some very pleasing results (Figs. 16-18).

The tissue which is present in many cases of Microtia in the form of a vertical lobule can be used later to create both the tragus as well as the ear lobule (Fig. 19).

Some minor defects like clefting of the ear lobule can be treated with a z-plasty (Fig. 20).

Acknowledgments:

Dr. Padam Singh Bhandari, Consultant Plastic Surgeon, Lok Nayak Hospital, New Delhi-2 has contributed the bulk of the illustrations in this chapter for which the compiler of these short notes acknowledges a huge debt. Dr. Parag Sahasrabuddhe and Dr. Parag Telang as well as Dr. Nitin Mokal have frequently contributed to these short notes in the past. Their debt is as usual acknowledged.